[ratmriot]

When i turn my headlights on on my seventy two the fuel guage drops exactly one quarter of a tank. Why? How could i fix this?

 

[John_Muha]

With a jumper wire try grounding the black ground wire on the fuel gage. See if that stops the gage from dropping. Guessing that one of the dash ground wires is loose. Car is using the dash lamps as ground. Works until you turn on the lights. Ground wires are around the wiper switch.